Why is my entire render white?
Based on the file that you uploaded and your question (which I have now edited accordingly), you are actually asking about material settings.

The model does have materials. The problem was that the World color, specifically the Ambient color was set to full white and was overriding everything and making the entire scene look as such.

Here is your render with your current settings.



Here is the same render with the Ambient color set to full white and the others changed to show the contrast.



Here is your render with only the world settings changed (to the default settings) and a hemi lamp instead of the point lamp that you had to make it a bit brighter.